net: hns3: fix for getting auto-negotiation state in hclge_get_autoneg

When phy exists, we use the value of phydev.autoneg to represent the
auto-negotiation state of hardware. Otherwise, we use the value of
mac.autoneg to represent it.

This patch fixes for getting a error value of auto-negotiation state in
hclge_get_autoneg().

Fixes: 46a3df9f ("net: hns3: Add HNS3 Acceleration Engine & Compatibility Layer Support")
Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c

@@ -2172,6 +2172,10 @@ static int hclge_get_autoneg(struct hnae3_handle *handle)
 {
 	struct hclge_vport *vport = hclge_get_vport(handle);
 	struct hclge_dev *hdev = vport->back;
+	struct phy_device *phydev = hdev->hw.mac.phydev;
+
+	if (phydev)
+		return phydev->autoneg;
 
 	return hdev->hw.mac.autoneg;
 }